package com.yvan.demo.mvc;

import com.yvan.platform.JsonWapper;
import lombok.Cleanup;
import org.springframework.core.Conventions;
import org.springframework.core.MethodParameter;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import javax.servlet.http.HttpServletRequest;
import java.io.InputStream;

public class JsonWapperResolver implements HandlerMethodArgumentResolver {
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return (parameter.getParameterType() == JsonWapper.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        HttpServletRequest request = (HttpServletRequest) webRequest.getNativeRequest();
        @Cleanup InputStream is = request.getInputStream();
        JsonWapper arg = new JsonWapper(is);
        String name = Conventions.getVariableNameForParameter(parameter);

        WebDataBinder binder = binderFactory.createBinder(webRequest, arg, name);
        mavContainer.addAttribute(BindingResult.MODEL_KEY_PREFIX + name, binder.getBindingResult());

        return arg;
    }
}
